Search

Chikungunya fever is an arboviral disease caused by the Chikungunya virus (CHIKV), which is classified into three genotypes, namely Asian, West African, and East/Central/South African (ECSA). Due to the frequency and severity of CHIKV outbreaks, it is crucial to genetically characterize the virus, especially in non-endemic regions. This report describes a case and genome characterization of CHIKV from a case that was detected in Jeddah (in 2021) during the COVID-19 pandemic. CHIKV was identified in a 32-year-old male patient in Jeddah, originally from India, who presented with fever, myalgia, malaise, and fatigue and was initially suspected of having dengue. The patient had no history of travel in the fortnight prior to his presentation. Treatment included paracetamol, saline, and vitamin C, which is important for the host immune response and detoxification of viral products. The genome of CHIKV was sequenced using various techniques and bioinformatics tools. Amino acid mutations were studied. Phylogenetic analysis showed that the CHIKV strain detected in 2021 was genetically distinct from those reported in 2018. The 2021 virus shared ancestry with CHIKV strains reported in India. This strain possessed E1-K211E, E2-V264A, and E1-I317V mutations. Novel substitutions were identified. The CHIKV re-emergence in 2021 in Jeddah belonged to the Indian subcontinent/Southeast Asia clade of ECSA. More molecular epidemiological information is needed to better understand and evaluate the prevalence of CHIKV in Saudi Arabia., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Dengue has been one of the major public health problems in Malaysia for decades. Over 600,000 dengue cases and 1,200 associated fatalities have been reported in Malaysia from 2015 to 2021, which was 100% increase from the cumulative total of dengue cases reported during the preceding 07-year period from 2008 to 2014. However, studies that describe the molecular epidemiology of dengue in Malaysia in recent years are limited. In the present study, we describe the genetic composition and dispersal patterns of Dengue virus (DENV) by using 4,004 complete envelope gene sequences of all four serotypes (DENV-1 = 1,567, DENV-2 = 1,417, DENV-3 = 762 and DENV-4 = 258) collected across Malaysia from 2015 to 2021. The findings revealed that DENV populations in Malaysia were highly diverse, and the overall heterogeneity was maintained through repetitive turnover of genotypes. Phylogeography analyses suggested that DENV dispersal occurred through an extensive network, mainly among countries in South and East Asia and Malaysian states, as well as among different states, especially within Peninsular Malaysia. The results further suggested Selangor and Johor as major hubs of DENV emergence and spread in Malaysia., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chem, Yenamandra, Chong, Mudin, Wan, Tajudin, Abu Bakar, Yamin, Yahya, Chang, Koo, Ng and Hapuarachchi.)

Background: In June 2023, a local cluster of 15 Zika cases was reported in a neighbourhood in Northeastern Singapore. The last significant local transmission of Zika virus (ZIKV) with more than 450 cases was in 2016-2017. To monitor the situation and mitigate further transmission, case, entomological and wastewater-based surveillance were carried out., Methods: Primary healthcare practitioners and the community were alerted to encourage timely case identification. Surveillance was enhanced through testing of Aedes mosquitoes collected from the National Gravitrap surveillance system, and wastewater samples were collected from a network of autosamplers deployed at manholes across the country., Findings: ZIKV RNA was detected in mosquito pools (3/43; 7%) and individual mosquitoes (3/82; 3.7%) captured, and in wastewater samples (13/503) collected from the vicinity of the cluster of cases. Respective samples collected from other sites across the country were negative. The peak detection of ZIKV RNA in mosquitoes and wastewater coincided temporally with the peak in the number of cases in the area (15-25 May 2023)., Interpretation: The restriction of ZIKV signals from wastewater and mosquitoes within the neighbourhood suggested limited ZIKV transmission. The subsequent waning of signals suggested effectiveness of control measures. We demonstrate the utility of wastewater-based surveillance of ZIKV, which complements existing case- and entomological-based surveillance. The non-intrusive approach is particularly useful to monitor diseases such as Zika, which generally causes silent or mild infections, but may cause severe outcomes such as congenital Zika syndrome., Funding: This study was funded by Singapore's Ministry of Finance and the National Environment Agency, Singapore., Competing Interests: Declaration of interests The authors have no conflicts of interest to declare., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The frequency of locally transmitted dengue virus (DENV) infections has increased in Europe in recent years, facilitated by the invasive mosquito species Aedes albopictus , which is well established in a large area of Europe. In Italy, the first indigenous dengue outbreak was reported in August 2020 with 11 locally acquired cases in the Veneto region (northeast Italy), caused by a DENV-1 viral strain closely related to a previously described strain circulating in Singapore and China. In this study, we evaluated the vector competence of two Italian populations of Ae. albopictus compared to an Ae. aegypti lab colony. We performed experimental infections using a DENV-1 strain that is phylogenetically close to the strain responsible for the 2020 Italian autochthonous outbreak. Our results showed that local Ae. albopictus is susceptible to infection and is able to transmit the virus, confirming the relevant risk of possible outbreaks starting from an imported case.